Abstract 4448: Development of DNA methylation biomarkers for pancreatic cancer diagnosis

Pancreatic cancer is highly lethal malignancy despite the recent clinical advancement. Since pancreatic cancer is often difficult to diagnose, there is an urgent need to develop minimally invasive biomarkers for detection. Epigenetic alterations have emerged as a common hallmark of many types of human cancers as well as pancreatic cancer. The presence of cell-free DNA (cfDNA) in blood stream has been known and cfDNA possesses tumor-related genetic alterations as well as epigenetic alterations. Therefore, invention of blood-based DNA methylation biomarkers and their high-sensitive detection system might be a promising diagnostic tool for pancreatic cancer. In order to establish the diagnostic biomarkers, first, we performed genome-wide DNA methylation analysis of 38 EUS-FNA specimens of pancreatic cancer with clinical stage III-IV using Illumina Infinium HumanMethylation450 BeadChip. We further analyzed the DNA methylation profiles of other types of tumors in the public database, TCGA (The Cancer Genome Atlas), and identified five marker genes, which were specifically methylated in pancreatic cancers. In addition, analysis of DNA methylation status of pancreas cancers comparing 10 normal tissues in TCGA data set revealed that 99% of tumors were methylated at least one of the five markers (sensitivity, 98.9%; specificity, 44%). We validated these methylation markers in different FNA sample set (n = 19) by bisulfite pyrosequencing or quantitative methylation specific PCR and found that 18/19 (95%) cases were methylated in at least one marker (AUC = 0.95). Finally, we performed methylation analysis in cfDNA from pancreatic cancer patients. From our preliminary data, we could detect aberrant DNA methylation in cfDNA from pancreatic cancer patients. We identified potential DNA methylation biomarkers for the diagnosis of pancreatic cancers and these markers might be applicable for detecting cancer in cfDNA. Citation Format: Keiko Shinjo, Keisuke Katsushima, Genta Nagae, Hiroyuki Aburatani, Kenji Yamao, Yutaka Kondo. Development of DNA methylation biomarkers for pancreatic cancer diagnosis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4448.